Coronary Multidetector Computed Tomography Research Articles

Evaluation of Coronary Atherosclerosis in Patients with Coronary Artery Aneurysm With CAD-RADS Scoring System Using MDCT Angiography

Aim: This article aims to investigate the degree and frequency of atherosclerosis using the “Coronary Artery Disease Reporting and Data System” (CAD-RADS) classification in patients who underwent coronary Multidetector Computed Tomography (MDCT) Angiography with a preliminary diagnosis of coronary artery disease and were found to have coronary artery aneurysm (CAA) and also to discuss the predisposing factors, prevalence, diagnostic criteria and complications in CAA with CT images.Material and Methods: We retrospectively evaluated the examinations of 3694 patients who underwent coronary MDCT angiography. We evaluated a total of 69 patients including 23 patients with CAA and 46 patients without CAA, in terms of atherosclerotic involvement using the CAD-RADS classification system and compared the findings.Results: CAA was most frequently found in the right coronary artery (RCA), followed by the left anterior descending artery (LAD), left circumflex (LCX), left main coronary artery (LMCA), and posterolateral branch (PLB). In patients with CAA, the most frequently atherosclerosis observed vessels were LAD, LCX, RCA, and LMCA, respectively, while LAD, RCA, LCX, LMCA, PLD, and PDA were detected in patients without an aneurysm. No atherosclerosis was detected in 5 patients (21.7 %) with CAA and 15 patients (32.6 %) without CAA (p>0.05). Conclusion: The number of atherosclerotic vessels and the degree of stenosis calculated using the CAD-RADS scoring in patients with CAA are similar to patients without an aneurysm. The fact that atherosclerosis is an important factor in the etiology of aneurysms may explain this situation.

Diltiazem for Reducing Heart Rate in Orthotopic Heart Transplant Patients During Coronary Computed Tomography Angiography

ObjectiveThis study sought to evaluate the effectiveness of diltiazem at achieving a targeted heart rate (HR) of ≤75 bpm in orthotopic heart transplant patients during coronary computed tomography (CT) angiography. MethodsBaseline heart rates were compared to heart rates after diltiazem administration in 25 adult orthotopic heart transplant subjects being monitored by electrocardiogram (ECG) gaiting on a multidetector CT scanner. ResultsThe mean baseline HR of the group was 84.28 ± 11.305 bpm. After diltiazem administration, the mean heart rate of the group at the time of the coronary CT angiography study was 75.32 ± 9.49 bpm. Heart rates decreased in 23 subjects (92%) and the targeted heart rate of ≤75 bpm was observed in 13 subjects (52%). ConclusionDiltiazem administration was associated with a decrease in heart rate, yet reaching the targeted heart rate was limited. Further study regarding diltiazem dosing and its impact is warranted.

Correlation of epicardial fat quantification with severity of coronary artery disease: A study in Indian population

ObjectiveWe studied the correlation of quantified epicardial fat with severity of coronary artery disease in patients [suspected cases of coronary artery disease (CAD)] referred for computed tomography (CT) coronary angiography and established cutoffs for epicardial fat volume (EFV) for the presence of CAD and obstructive CAD. MethodsA prospective cum retrospective cross-sectional observational study was carried out on 950 Indian subjects (suspected cases of CAD) who were referred for coronary CT in the year 2013–2016. EFV was quantified using semiautomatic technique on multidetector coronary CT angiography. The presence of atherosclerotic plaques and degree of stenosis was assessed on coronary CT angiography scans. The correlation between quantified EFV and degree of stenosis was assessed. Multivariate analysis was also performed. ResultsA higher quantity of epicardial fat is found in patients with increasing severity of coronary artery stenosis. The EFV cutoff for the presence of CAD and obstructive CAD are 49.75 and 67.69 mL with area under the curve, sensitivity, specificity, positive predictive value, negative predictive value, and diagnostic accuracy of 0.68, 81%, 45.9%,58.24%, 72.2%, and 62.84% and 0.709, 64.9%, 66.4%, 35.84%, 86.55%, and 66%, respectively. EFV correlates with age, weight, and body mass index (BMI). Multivariate analysis revealed EFV to be an independent risk factor for the presence of CAD. ConclusionsHigher quantities of EFV are found in patients with greater degree of coronary artery stenosis. EFV correlates with age, weight, and BMI. EFV is an independent risk factor for CAD.

Poor long-term outcomes in stroke patients with asymptomatic coronary artery disease in heart CT

Background and aimsAlthough stroke patients have a high risk of ischemic heart disease, little information is available on the risk of coronary events in stroke patients with asymptomatic coronary artery disease (CAD). We investigated the long-term vascular outcomes in stroke patients with asymptomatic CAD diagnosed with multi-detector coronary computed tomography (MDCT). MethodsThis study was a retrospective analysis using a prospective cohort of ischemic stroke patients. We included consecutive stroke patients without history or symptoms of CAD who underwent MDCT. We investigated the long-term risk of major adverse cardiovascular events (MACE: cardiovascular mortality, ischemic stroke, myocardial infarction, unstable angina, and urgent coronary revascularization) and composite of MACE/all-cause mortality/elective coronary revascularization. We further investigated the value of MDCT for MACE prediction. ResultsAmong the 1893 included patients, 1349 (71.3%) patients had some degree of CAD and 654 patients (34.5%) had significant (≥50%) CAD. At follow-up (median, 4.4 years), MACE occurred in 230 patients (12.2%). Event rates of MACE increased with the increasing extent of CAD. After adjustment for age, sex, and risk factors, the hazard ratios for MACE in mild CAD, 1-VD, 2-VD, and 3-VD or left main coronary disease were 1.28 (95% confidence interval [CI]: 0.88–1.87), 1.39 (95% CI: 0.90–2.16), 2.22 (95% CI: 1.39–3.55), and 2.91 (95% CI: 1.82–4.65), respectively (no CAD as a reference). Diagnosis of asymptomatic CAD significantly improved the prediction of MACE. ConclusionsAsymptomatic CAD detected on MDCT was associated with increased risks of vascular events or deaths in acute stroke patients.

Association of Dyslipidemia and Sex With Coronary Artery Calcium Assessed by Coronary Computed Tomography Angiography.

Previous studies reporting that statin increases coronary artery calcium (CAC) were conducted exclusively on patients with statin as a prevention, regardless of the presence or absence of dyslipidemia. The impact of sex on CAC has not been fully evaluated. We aimed to determine the association of dyslipidemia and sex with CAC using 320-row multi-detector computed tomography (MDCT).Of the 356 consecutive patients who underwent coronary MDCT, 251 patients were enrolled, after excluding those with prior stenting and/or coronary bypass grafting or images showing motion artifacts. The primary outcome measures were the percent calcium volume (PCV) and percent atheroma volume (PAV) per coronary vessel.Multivariable analyses indicated that PCV was significantly higher in dyslipidemia patients without statins than in the subjects without dyslipidemia [partial regression coefficient (PRC): 2.59, 95% confidence interval (CI): 0.83 to 4.34, P = 0.004]. In contrast, PCV was similar in dyslipidemia patients taking statins and those without dyslipidemia (PRC: -1.09, 95% CI: -2.82 to 0.65, P = 0.22). There was no significant difference in PCV between men and women, although women exhibited a significantly lower PAV (PRC: -2.87, 95% CI: -4.54 to -1.20, P = 0.001).In low-risk patients, these results could be translated into hypotheses, which should be tested in future prospective studies. Furthermore, there was no significant difference in CAC between men and women, but women had lower PAV than men.

Prevalence of cardiac and extracardiac incidental findings in the evaluation of coronary artery disease by multidetector computed tomography

With the widespread use of multidetector computed tomography (MDCT) coronary angiography, cardiac and extracardiac incidental findings in cardiac imaging might be detected. The aim of this study was to determine the prevalence of cardiac and extracardiac incidental findings in a population of consecutive patients undergoing coronary MDCT. A total of 840 consecutive patients with known or suspected heart disease underwent cardiac MDCT. All patients were assessed with 64-slice MDCT; the examination was performed by limiting the anatomical region examined between the bifurcation of the trachea and the cardiac apex with the aim of obtaining excellent image quality and low cardiac radiological exposure. Overall, 81 incidental findings in 72 patients (9%) were identified, of which 18 were cardiac (2%) and 63 extracardiac (7%). Extracardiac incidental findings were mainly represented by pulmonary nodules (19%). A significant number of cardiac and extracardiac incidental findings were observed at cardiac MDCT, with the prevalence depending on technical aspects of image acquisition and patient characteristics. Incidental findings should be carefully searched for and reported because they may have an impact on clinical follow-up indications that is not without cost and risk.

Prevalence and significance of clinically unsuspected pulmonary embolism: detection using coronary computed tomography angiography.

Clinically unsuspected pulmonary embolism can be detected using coronary computed tomography (CT), but the clinical significance of unsuspected pulmonary embolism remains unclear. Pulmonary embolism was assessed using consecutive coronary CT from March 2003 to June 2007 to assess 1077 patients. Coronary CT was performed using a 16-row multidetector CT (MDCT) scanner with ECG-gating. A radiologist and a cardiologist retrospectively assessed the images of pulmonary arteries to arrive at a consensus diagnosis. Unsuspected pulmonary embolism was detected in 32/1,077 (3.0%) patients. No significant difference was observed with regard to death and acute pulmonary embolism between patients with and without unsuspected pulmonary embolism at five years (6.7% vs. 4.1%, p = 0.61). Prior cardiac surgery within three months of diagnosis of pulmonary embolism was an independent risk factor for unsuspected pulmonary embolism, which was detected in 10/89 (11%) of such patients. The absence of anticoagulant therapy was a risk factor (p = 0.015) for unsuspected pulmonary embolism post-cardiac surgery. Although only one out of 10 patients received anticoagulant therapy, none of the 10 experienced critical events. Five of the 10 patients underwent repeated coronary CT, and the embolus disappeared regardless of its size and location in four of the five patients who did not receive anticoagulant therapy. The prevalence of unsuspected pulmonary embolism detected using coronary CT was 3.0%. Prior cardiac surgery within three months of diagnosing pulmonary embolism was an independent risk factor for unsuspected pulmonary embolism. The long-term clinical outcomes of patients with unsuspected pulmonary embolism were favorable.

Fusion Image of Coronary Artery and Myocardial Perfusion Using Computed Tomography

Coronary angiography of 64-year-old man with chest pain shows the total occlusion (Fig 1, arrows) in the proximal portion of the left ascending coronary artery (LAD). Stress perfusion cardiac magnetic resonance image (MRI) depicts endocardium hypoperfusion area in the LAD territory and late gadolinium enhancement MRI showed subendocardial infarction. In this case, fusion image of coronary computed tomography (CT) and perfusion CT can present coronary lesions and following myocardial ischemia precisely. Pre-coronary artery bypass grafting (CABG) epicardial image shows the hypoperfusion area in LAD territory (Fig 2A, arrows), and subendocardial image shows the severe hypoperfusion lesion (Fig 2B, arrows). Transmural ischemic changes that were mainly seen in the anteroseptal wall were improved in the epicardium (Fig 2C) after CABG. However, subendocardial image shows residual ischemia in the subendocardium (Fig 2D, arrows), which suggests that blood flow could not be improved sufficiently with subendocardial infarction. Combined technique with perfusion CT using a 256-slice multidetector CT and a time axis interpolation technique [1Wai B. Thai W.E. Brown H. Truong Q.A. Novel phase-based noise reduction strategy for quantification of left ventricular function and mass assessment by cardiac CT: comparison with cardiac magnetic resonance.Eur J Radiol. 2013; 82: e337-e341Abstract Full Text Full Text PDF PubMed Scopus (18) Google Scholar] allowed us to assess CT attenuation independent stratified myocardial ischemia.

Multislice CT coronary angiography is an additional tool for provisional diagnosis of acute chest pain with neither ECG nor echocardiography significant findings in emergency room

Background Multislice coronary computed tomography (CT) angiography is used to diagnose coronary artery disease (CAD) with good spatial and temporal resolution. Objective The aim of this study was to assess the uses of thin-slice multidetector row CT in the diagnosis of different vascular coronary causes of chest pain. Patients and methods A total of 20 patients were examined with full history taking, resting 12-lead ECG, cardiac biomarkers, and echocardiography. Thereafter, on the basis of their clinical manifestations or suspected progression of past condition they were enrolled for 160-multislice CT angiography using Ultravist 370 as a contrast medium. Results CT coronary angiography revealed the following: two cases were normal, two showed nonsignificant CAD, three showed significant CAD, 10 showed mild-to-moderate CAD, two showed anomalous coronary arteries, and one showed myocardial bridge. Conclusion CT angiography nowadays is considered the primary tool of diagnosis for different thoracic vascular disorders, being a safe, rapid method of diagnosis. Multislice coronary CT is a relatively new technique that gives physicians the advantage of screening emergency patients presenting with acute chest pain in a rapid and safe way for detection of their vascular diseases.

Case of Double Right Coronary Artery: Diagnosed on Computed Tomography Coronary Angiography

Anomalies of the coronary artery are often asymptomatic and uncommon. Double right coronary artery (RCA) is a very rare coronary anomaly. So far, the number of reported cases of double RCA is not many. Nevertheless, there have been several reports of double RCA in the literature, particularly in the last decade. We aim to present a similar case. Multidetector computed tomography (CT) is becoming an alternative method for the diagnosis of coronary artery anomalies. We present the multidetector coronary CT angiography findings from a patient with RCA duplication. Two right coronary arteries originating from two separate ostia of the right aortic sinus were observed.

Comparison of the accuracy of cardiac computed tomography angiography and transthoracic echocardiography in the diagnosis of mitral valve prolapse.

Background:Cardiac multidetector computed tomography (MDCT) has been mainly applied in the diagnosis of valvular heart morphology and function along with the assessment of coronary artery disease. This study aimed to evaluate the diagnostic performance of coronary MDCT angiography for the diagnosis of mitral valve prolapse (MVP), as compared to transthoracic echocardiography (TTE).Materials and Methods:A total of 40 patients who had undergone both TTE and MDCT within a three-month period were included in the study. Two parameters of mitral valve leaflet thickness and leaflet billowing were measured using both techniques. The MDCT results were compared with those of TTE, which was the reference standard.Results:Implementing the Receiver Operating Characteristic (ROC) test on the data for MDCT-measured leaflet billowing received from MDCT angiography suggests that the area under the ROC curve is 96% for a declared variable, which is absolutely significant (P < 0.001), and MDCT-measured leaflet billowing is an appropriate index for the diagnosis of mitral valve prolapse. On the basis of the achieved cut-off point from the ROC analysis (which equals 2.5 mm leaftlet billowing) the MDCT-measured leaflet billowing takes a sensitivity and specificity of 68.4 and 95.2%. The false positive and false negative results are 4.8 and 31.6%. The positive and negative predictive values (PPV and NPV) of the revealed test indicate 92.9 and 76.9%, respectively. Finally, the consistency of the MDCT measured leaflet billowing for diagnosing the mitral valve prolapse is 82.5%. Based on the mentioned test, the consistency of the MDCT-measured leaflet thickness test is 47.5%.Conclusion:Along with the assessment of coronary arteries, the presence or absence of MVP can be reliably evaluated by MDCT angiography.

Role of cardiac multidetector computed tomography in the exclusion of ischemic etiology in heart failure patients

Introduction and AimsDifferentiation of ischemic from non-ischemic etiology in heart failure (HF) patients has both therapeutic and prognostic implications. One possible approach to this differentiation is direct visualization of the coronary tree. Multidetector computed tomography (MDCT) has emerged as an alternative to invasive coronary angiography (ICA), but its performance and additional clinical value are still not well validated in patients with left ventricular (LV) dysfunction. We aimed to assess the value of coronary MDCT angiography (CTA) in the exclusion of ischemic etiology in HF patients and to determine whether the Agatston calcium score could be used as a gatekeeper for CTA in this context. MethodsWe retrospectively selected symptomatic HF patients with LV ejection fraction (LVEF) <50%, as assessed by echocardiography, referred for CTA between April 2006 and May 2013. Patients with previously known CAD or valvular disease were excluded. The performance of MDCT in the detection of coronary artery disease (CAD) and/or exclusion of an ischemic etiology for HF was studied. Obstructive CAD was defined as the presence of ≥50% luminal stenosis in at least one epicardial coronary artery as assessed by CTA and was assumed in patients with an Agatston coronary artery calcium (CAC) score >400. In patients referred for ICA, an ischemic etiology was assumed in the presence of ≥75% stenosis in two or more epicardial vessels or ≥75% stenosis in the left main or proximal left anterior descending artery. ResultsDuring this period 100 patients (mean age 57.3±10.5 years, 64% men) with HF and systolic dysfunction were referred for MDCT to exclude CAD. Median effective radiation dose was 4.8 mSv (interquartile range 5.8 mSv). Mean LVEF was 35±7.7% (range 20-48%) and median CAC score was 13 (interquartile range 212). Seven patients were in atrial fibrillation.Almost half of the patients (40%) had no CAC and none of these had significant stenosis on CTA. In an additional group of 33 patients CTA was able to confidently exclude obstructive CAD. Twenty-seven patients were classified as positive for CAD (16 due to CAC >400 and 11 with ≥50% stenosis) and were associated with lower LVEF (p=0.004). Of these, 21 patients subsequently underwent ICA: obstructive CAD was confirmed in nine and only six had criteria for ischemic cardiomyopathy. ConclusionIn our HF population, MDCT was able to exclude an ischemic etiology in 73% of cases in a single test. According to our results the Agatston calcium score may serve as a gatekeeper for CTA in patients with HF, with a calcium score of zero confidently excluding an ischemic etiology.

Role of cardiac multidetector computed tomography in the exclusion of ischemic etiology in heart failure patients

Introduction and AimsDifferentiation of ischemic from non-ischemic etiology in heart failure (HF) patients has both therapeutic and prognostic implications. One possible approach to this differentiation is direct visualization of the coronary tree. Multidetector computed tomography (MDCT) has emerged as an alternative to invasive coronary angiography (ICA), but its performance and additional clinical value are still not well validated in patients with left ventricular (LV) dysfunction. We aimed to assess the value of coronary MDCT angiography (CTA) in the exclusion of ischemic etiology in HF patients and to determine whether the Agatston calcium score could be used as a gatekeeper for CTA in this context. MethodsWe retrospectively selected symptomatic HF patients with LV ejection fraction (LVEF) <50%, as assessed by echocardiography, referred for CTA between April 2006 and May 2013. Patients with previously known CAD or valvular disease were excluded. The performance of MDCT in the detection of coronary artery disease (CAD) and/or exclusion of an ischemic etiology for HF was studied. Obstructive CAD was defined as the presence of ≥50% luminal stenosis in at least one epicardial coronary artery as assessed by CTA and was assumed in patients with an Agatston coronary artery calcium (CAC) score >400. In patients referred for ICA, an ischemic etiology was assumed in the presence of ≥75% stenosis in two or more epicardial vessels or ≥75% stenosis in the left main or proximal left anterior descending artery. ResultsDuring this period 100 patients (mean age 57.3±10.5 years, 64% men) with HF and systolic dysfunction were referred for MDCT to exclude CAD. Median effective radiation dose was 4.8 mSv (interquartile range 5.8 mSv). Mean LVEF was 35±7.7% (range 20-48%) and median CAC score was 13 (interquartile range 212). Seven patients were in atrial fibrillation.Almost half of the patients (40%) had no CAC and none of these had significant stenosis on CTA. In an additional group of 33 patients CTA was able to confidently exclude obstructive CAD. Twenty-seven patients were classified as positive for CAD (16 due to CAC >400 and 11 with ≥50% stenosis) and were associated with lower LVEF (p=0.004). Of these, 21 patients subsequently underwent ICA: obstructive CAD was confirmed in nine and only six had criteria for ischemic cardiomyopathy. ConclusionIn our HF population, MDCT was able to exclude an ischemic etiology in 73% of cases in a single test. According to our results the Agatston calcium score may serve as a gatekeeper for CTA in patients with HF, with a calcium score of zero confidently excluding an ischemic etiology.

Association of metabolically healthy obesity (MHO) with subclinical coronary atherosclerosis in a Korean population

The degree of subclinical coronary atherosclerosis detected by coronary multidetector computed tomography (MDCT) in four groups defined by the state of metabolic health and obesity in an asymptomatic Korean population was compared. The data of 4009 asymptomatic subjects who participated in a routine health screening examination were collected. Significant coronary artery stenosis defined as >50% stenosis, plaque, and coronary artery calcium scores (CACS) were assessed by MDCT. Participants were stratified by BMI (cut-off value, 25 kg/m(2) ) and metabolically healthy state, which was defined by Wildman criteria. Metabolically healthy obese (MHO) subjects had a significantly higher prevalence of significant subclinical coronary atherosclerotic burden compared with metabolically healthy nonobese (MHNO) subjects. The adjusted odds ratios of the MHO group for various coronary MDCT findings (MHNO group as the reference), such as coronary artery stenosis, any plaque, calcified plaque, mixed plaque, CACS > 0, and CACS > 100, were 1.87 (95% CI 1.15-3.03), 1.31 (1.01-1.71), 1.40 (1.05-1.86), 1.57 (1.01-2.48), 1.38 (1.04-1.82), and 1.69 (1.03-2.78), respectively. Our data illustrate that MHO subjects have substantial subclinical coronary atherosclerotic burden. Thus, it is important to consider the metabolic health state and obesity in evaluating cardiovascular risk.

Diagnostic accuracy of multidetector computed tomography coronary angiography in 325 consecutive patients referred for transcatheter aortic valve replacement

Multidetector computed tomography (MDCT) provides detailed assessment of valve annulus and iliofemoral vessels in transcatheter aortic valve replacement (TAVR) patients. However, data on diagnostic performance of MDCT coronary angiography (MDCT-CA) are scarce. The aim of the study is to assess diagnostic performance of MDCT for coronary artery evaluation before TAVR. A total of 325 consecutive patients (234 without previous myocardial revascularization, 49 with previous coronary stenting, and 42 with previous coronary artery bypass graft [CABG]) underwent invasive coronary angiography and MDCT before TAVR. MDCT-CA was performed using the same data set dedicated to standard MDCT aortic annulus evaluation. Multidetector computed tomography-CA evaluability and diagnostic accuracy in comparison with invasive coronary angiography as criterion standard were assessed. The MDCT-CA evaluability of native coronaries was 95.6%. The leading cause of unevaluability was beam-hardening artifact due to coronary calcifications. In a segment-based analysis, MDCT-CA showed sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and accuracy for detecting ≥50% stenosis of 91%, 99.2%, 83.4%, 99.6% and 98.8%, respectively. The MDCT-CA evaluability of coronary stents was 82.1%. In a segment-based analysis, MDCT-CA showed sensitivity, specificity, PPV, NPV, and accuracy for detecting ≥50% in-stent restenosis of 94.1%, 86.7%, 66.7%, 98.1%, and 88.3%, respectively. All CABGs were correctly assessed by MDCT-CA. In a patient-based analysis, MDCT-CA showed sensitivity, specificity, PPV, NPV, and accuracy of 89.7%, 90.8%, 80.6%, 95.4%, and 90.5%, respectively. Multidetector computed tomography-CA allows to correctly rule out the presence of significant native coronary artery stenosis, significant in-stent restenosis, and CABG disease in patients referred for TAVR.

Multi-Detector Coronary CT Imaging for the Identification of Coronary Artery Stenoses in a "Real-World" Population.

BACKGROUNDMulti-detector computed tomography (CT) has emerged as a modality for the non-invasive assessment of coronary artery disease (CAD). Prior studies have selected patients for evaluation and have excluded many of the “real-world” patients commonly encountered in daily practice. We compared 64-detector-CT (64-CT) to conventional coronary angiography (CA) to investigate the accuracy of 64-CT in determining significant coronary stenoses in a “real-world” clinical population.METHODSA total of 1,818 consecutive patients referred for 64-CT were evaluated. CT angiography was performed using the GE LightSpeed VCT (GE® Healthcare). Forty-one patients in whom 64-CT results prompted CA investigation were further evaluated, and results of the two diagnostic modalities were compared.RESULTSA total of 164 coronary arteries and 410 coronary segments were evaluated in 41 patients (30 men, 11 women, age 39–85 years) who were identified by 64-CT to have significant coronary stenoses and who thereafter underwent CA. The overall per-vessel sensitivity, specificity, positive predictive value, negative predictive value, and accuracy at the 50% stenosis level were 86%, 84%, 65%, 95%, and 85%, respectively, and 77%, 93%, 61%, 97%, and 91%, respectively, in the per-segment analysis at the 50% stenosis level.CONCLUSION64-CT is an accurate imaging tool that allows a non-invasive assessment of significant CAD with a high diagnostic accuracy in a “real-world” population of patients. The sensitivity and specificity that we noted are not as high as those in prior reports, but we evaluated a population of patients that is typically encountered in clinical practice and therefore see more “real-world” results.

Diagnostic accuracy of multidetector computed tomography coronary angiography in 330 consecutive patients referred for balloon-expandable transcatheter aortic valve implantation

Purpose: The aim of this study was to assess the evaluability and diagnostic accuracy of the multidetector computed tomography (MDCT) coronary angiography in patients referred for transcatheter aortic valve implantation (TAVI). MDCT is playing an increasingly role in patients scheduled for TAVI, providing detailed anatomic assessment of the aortic root and valve annulus and of iliofemoral access. However, the diagnostic performance of MDCT coronary angiography has not been well investigated. Methods: 330 consecutive patients scheduled for invasive coronary angiography (ICA) and 64-slice MDCT for the screening protocol before TAVI were enrolled (42 patients with previous coronary artery bypass graft (CABG), 49 with previous coronary stenting, 233 without previous revascularizations). All MDCT coronary angiography were performed using the same data set dedicated to the standard MDCT evaluation of aortic annulus, obtained with retrospective ECG triggering. Coronary arteries evaluability by MDCT coronary angiography and its diagnostic accuracy parameters in comparison with ICA as gold standard were evaluated. Results: In the remaining 325 patients, the mean HR during the scan was 61±9 bpm. The MDCT evaluability of native coronary arteries was 95.6%. The leading cause of unevaluability was the beam-hardening artifact due to large coronary calcifications (109 cases), followed by slice misalignments (56 cases) due to HR variability or premature heart beats during the scan and motion artifacts (40 cases). In the segment-based analysis, sensibility, specificity, positive predictive value, negative predictive value and accuracy were 91%, 99.2%, 83.4%, 99.6% and 98.8%, respectively. MDCT correctly assessed the patency of all CABG, without graft classified as non evaluable. The MDCT evaluability of coronary stents was 82.1%. In the segment-based analysis, MDCT showed sensibility, specificity, positive predictive value, negative predictive value and accuracy for the detection of ≥ 50% luminal narrowing of 94.1%, 86.7%, 66.7%, 98.1% and 88.3%, respectively. Conclusions: MDCT coronary angiography allows to correctly rule out the presence of significant coronary stenosis in patients referred for TAVI, demonstrating and excellent negative predictive value also in patients with previous CABG or stents.

Diagnostic value of cardiac multi-detector computed tomography for detection of subclinical atherosclerosis in asymptomatic diabetic patients

Purpose: Silent myocardial ischemia in asymptomatic subjects with no history of ischemic heart disease is a frequent condition in diabetic patients. Therefore the detection of subclinical atherosclerosis in asymptomatic diabetic patients is important. The aim of the present study was to investigate the prevalence, characteristics, and prognostic value of coronary 64-slice multi-detector computed tomography (MDCT) in asymptomatic diabetic patients. Methods: We retrospectively enrolled self-referred 444 diabetic patients (age = 58.2±8.3 years, 326 males) who underwent both coronary MDCT angiography and coronary calcium scoring from January 2008 to June 2011. For all subjects, we evaluated clinical risk factors and investigated cardiac events. Subclinical atherosclerosis was defined as the any detectable plaques on MDCT and significant stenosis was defined as more than 75% narrowing of coronary artery diameter in this study. Results: Subclinical atherosclerosis was found in 214 subjects (48.2%). The subclinical atherosclerosis group was older, more patients with male, smokers, high level of fasting serum glucose. Independent predictors of subclinical atherosclerosis were old age (≥ 65years) [odds ratio (OR): 1.099, 95% confidence interval (CI): 1.01-1.19, p=0.022], and high level of HbA1C (≥ 7.0%) (HR: 1.64, 95% CI: 1.02-2.66, p=0.042) in multivariate logistic regression analysis. And significant coronary stenosis in MDCT was found in 83 patients (18.7%). The significant stenosis group was older, more patients with hypertension, smokers, high level of high sensitivity C-reactive protein (hs-CRP). High level of hs-CRP high (≥ 2mg/L) was an independent predictor of significant stenosis (OR: 2.66, 95% CI: 1.67-4.02, p=0.012). 71 patients who showed significant stenosis underwent stress test, such as treadmill exercise test or myocardial SPECT. Among them, 48 patients underwent conventional coronary angiogram and 20 patients underwent percutaneous coronary intervention. During clinical follow-up (mean follow-up period=21.5±11.3 months), of all subjects myocardial infarction was developed in 3, unstable angina in 17, target lesion revascularization in 4 patients. Conclusions: In this study, the prevalence of subclinical coronary atherosclerosis in asymptomatic diabetic patients was nearly fifty percent. Cardiac MDCT will be an useful method for detection of subclinical atherosclerosis in diabetic patients.

Coronary artery fistulas in children

There are various types of coronary artery fistulas (CAF) with complex shapes. Therefore, it is important to make a correct diagnosis and to understand the relationship of the CAF to the adjacent structures before transcatheter occlusion or surgery. This study evaluated the feasibility of using 64-slice multidetector computed tomography (MDCT) angiography in diagnosing CAF. Two readers who were blinded to the results of echocardiography, intervention, or surgery retrospectively evaluated the coronary MDCT appearances of CAF in 10patients (4boys and 6girls; mean age, 2.9years; range, 1-6years). The origin, course, and distal entry site of the fistula were determined. The diameters of the origin and the distal entry site were measured and compared with those seen during intervention or surgery. The origin, course, and distal vessel entry site of the CAF were clearly outlined in all patients by MDCT. The distal vessel draining site involved a single entry vessel in all patients. Seven fistulas involved the right coronary artery, and three involved the left coronary artery. Four fistulas drained into the right ventricle, four into the right atrium, and two into the left ventricle. The diagnosis of CAF using MDCT was in accordance with diagnoses made during intervention or surgery. There was an excellent correlation between MDCT and transcatheter occlusion in quantifying the diameters of the origin and distal entry site (R = 0.90 and 0.92, respectively, P < 0.05). Coronary 64-slice MDCT angiography depicted the whole shape and course of the CAF as well as of the surrounding structures. It may serve as a noninvasive diagnostic tool when planning a therapeutic strategy.

Association of Apolipoprotein B/Apolipoprotein A1 Ratio and Coronary Artery Stenosis and Plaques Detected by Multi-Detector Computed Tomography in Healthy Population

Despite the noninvasiveness and accuracy of multidetector computed tomography (MDCT), its use as a routine screening tool for occult coronary atherosclerosis is unclear. We investigated whether the ratio of apolipoprotein B (apoB) to apolipoprotein A1 (apoA1), an indicator of the balance between atherogenic and atheroprotective cholesterol transport could predict occult coronary atherosclerosis detected by MDCT. We collected the data of 1,401 subjects (877 men and 524 women) who participated in a routine health screening examination of Asan Medical Center. Significant coronary artery stenosis defined as > 50% stenosis was detected in 114 subjects (8.1%). An increase in apoB/A1 quartiles was associated with increased percentages of subjects with significant coronary stenosis and noncalcified plaques (NCAP). After adjustment for confounding variables, each 0.1 increase in serum apoB/A1 was significantly associated with increased odds ratios (ORs) for coronary stenosis and NCAP of 1.23 and 1.18, respectively. The optimal apoB/A1 ratio cut off value for MDCT detection of significant coronary stenosis was 0.58, which had a sensitivity of 70.2% and a specificity of 48.2% (area under the curve, 0.61; 95% CI, 0.58-0.63, P < 0.001). Our results indicate that apoB/A1 ratio is a good indicator of occult coronary atherosclerosis detected by coronary MDCT.